Normal fatty acid concentrations in young children with phenylketonuria

The objective of this study was to determine whether children with phenylketonuria (PKU) have lower fatty acid concentrations in total erythrocyte lipid due to the phenylalanine-restricted diet therapy compared to healthy control subjects. Dietary intake and fatty acid concentrations in total erythrocyte lipid were measured in 21 subjects (≤6 years of age) with PKU and 23 control children. Subjects with PKU had significantly lower protein and significantly higher polyunsaturated fat intake than controls. Subjects with PKU had significantly lower concentrations in total erythrocyte lipid of the sum of the ω-3, ω-6, saturated, and polyunsaturated fatty acids. Concentrations of fatty acids among subjects with PKU were lower than those among control subjects, but no subject with PKU exhibited any signs or symptoms suggestive of essential fatty acid deficiency, thereby suggesting that subjects with PKU in this cohort had normal and adequate essential fatty acid concentrations in total erythrocyte lipid.